1. Technical Field of the Invention
The present invention relates to a coupling device to be provided between left and right wheels of a vehicle such as a motor vehicle, in particular between the left and right idler wheels that are not driven by an engine.
2. Description of the Related Art
Conventionally, as this kind of coupling device, there is known, in Japanese Published Unexamined Patent Application No. 79348/1997, a coupling device comprising: an electric motor; and a switching mechanism which can be switched between the following two states, i.e., a state in which the starting of a vehicle is assisted by transmitting a toque from the electric motor to the left and right wheels in the same direction of rotation, and a state in which cornering of the vehicle is assisted by transmitting from the electric motor to one of the left and right wheels a torque to accelerate said one of the wheels relative to the other of the wheels.
At the time of starting or cornering of the vehicle, it is desirable to indicate an operating condition of the coupling device to inform a driver of the vehicle whether a starting assistance or cornering assistance is being performed or not.
The present invention has an object of providing between the left and right wheels a coupling device which is suitable to meet this kind of desire.